A 4 year old patient was admitted to the Emergency Department of Hospital Regional de Cusco with 17 days history of a rat bite. One week later, the patient developed fever and rash, which lasted for 3 days. Fever, an abscess on the forehead with lymphangitis, and cervical lymphadenopathy were observed on admission. The VDRL test was positive but FTA-Abs was negative. He was diagnosed of rat bite fever and treated with IV penicillin G with a favorable response. The case is discussed and pertinent literature is reviewed. (Rev Med Hered 2003; 14:44-47).